Measured Wind Waves in Lake Pontchartrain
During Hurricane Katrina
AU: * McGehee, D D
Email:
AF: Emerald Ocean
Engineering LLC, 107 Ariola Drive, Pensacola Beach, FL 32561 US
AU: Winer, H Email:
Harley.S.Winer@mvn02.usace.army.mil
AF: US Army Corps of
Engineers New Orleans District, 7400 Leake Ave., New Orleans, LA 70118-3651 US
AU: Earle, M Email:
MEarle@PLANSYS.COM
AF: Neptune Sciences
Division, Planning Systems Inc., 40201 Hiway 190 East, Slidell, LA 70461 US
AU: Smith, R Email:
RSmith@PLANSYS.COM
AF: Neptune Sciences
Division, Planning Systems Inc., 40201 Hiway 190 East, Slidell, LA 70461 US
AU: Mesa, C
Email: Chuck.Mesa@spl01.usace.army.mil
AF: US Amy Corps of
Engineers, Los Angeles District, P.O. Box 532711, Los Angeles, CA 90053-2325 US
AU: Pollock, C
Email:
Cheryl.E.Pollock@erdc.usace.army.mil
AF: US Army Engineer
research and Development Center, 3909 Halls Ferry Road, Vicksburg, MS 39180 US
AU: Hughes, B
Email: WHughes@PLANSYS.COM
AF: Neptune Sciences Division, Planning
Systems Inc., 40201 Hiway 190 East, Slidell, LA 70461 US
ABSTRACT
A program for capturing
episodic wave data in Lake Pontchartrain, LA using miniature rapidly-deployable
wave buoys was implemented by the US Army Engineer District New Orleans. The
data were intended for calibration and validation of numerical wave models used
to investigate the risk of catastrophic flooding of New Orleans due to
overtopping of the levees on the south shore of the lake. Several deployments
during moderate storm events over the last three years demonstrated the
viability of the approach, which relied on internal storage of the data and
post-event recovery of the gages. Two days before landfall of Hurricane
Katrina, three of the miniature buoys were deployed about « mile offshore, just
north of the 17th Street Canal. Winds were from the northern quadrant when
Hurricane Katrina made landfall east of New Orleans, placing the levees, and
the gages, at the locus of maximum fetch during the highest wind speeds. By the
next day it was evident that the gages had encountered the event that was only
supposed to be simulated. Capturing the data, however, was dependent upon
recovering the buoys as soon as possible from a post-storm disaster scene that
few had envisioned. This paper describes the extreme episodic data capture
strategy, the gages, the sampling scheme, and the deployment and recovery
methodology. One-dimensional energy spectra and non-directional wave parameters
from two adjacent gages are compared and the quality control process is
described. The final quality-assured data set of the entire storm event, from
two days before landfall through 6 days afterward is presented. Lessons learned
to improve efficiency and reliability of the system are discussed.